"I believe that Microsoft is struggling to convince people that the constant upgrade and change of OSes is a requirement. Let's face it, while the multiple features that Windows 10 provides are useful in the home environment, most companies do not need any of these new features," said Castleman.

However, the move to block updates is contentious, because a number of businesses rely on software that is not supported by newer operating systems, or are already set up to support Windows 7, making the upgrade to Windows 10 a difficult proposition.

Gartner research VP Steve Kleynhans points out that Microsoft never said the latest Windows updates wouldn't work on Windows 7/8.1 systems running on newer processors, so a third party re-enabling updates on these systems is not surprising.

"Of course the block is artificial, but it is pre-emptive. The issue is that Windows 7 and Windows 8.1 are unsupported with the new processors, not that they don't work," he said.

"As Microsoft creates new fixes for Windows 7 and 8.1 it won't be testing them on those processors. Just because it works right now doesn't mean it will keep working with future fixes.

"Could Microsoft keep it working? Yes, but Windows 7 is already out of mainstream support, and Windows 8.1 has really small market penetration in enterprises.

"Microsoft doesn't want to divert the resources it would take to properly test out all the variations that would exist away from more important areas."

The rationale for no longer testing old OSes on newer hardware is that it is becoming increasingly complicated to do so, according to Microsoft.

"Windows 7 was designed nearly 10 years ago before any x86/x64 SOCs existed," Terry Myerson, EVP of Microsoft's Windows and Devices Group, said in a blogpost last year.

"For Windows 7 to run on any modern silicon, device drivers and firmware need to emulate Windows 7's expectations for interrupt processing, bus support, and power states, which is challenging for Wi-Fi, graphics, security, and more."

Gartner's Kleynhans has sympathy with the argument that the complexity of continuing to support these processors in older systems is becoming untenable.

"New processors today contain much more of the total logic that makes up a PC. They are much more integrated.

"There are a ton of drivers associated with the processor, in particular around UEFI and boot-loading processes, and the whole thing is kind of a jenga tower just waiting to collapse."

The issue that vexes some Windows users is whether Microsoft has the right to abandon its longstanding commitment to support Windows for 10 years after release, regardless of the hardware it runs on.

"All this is setting a very bad precedent in software and hardware industry, and I really hope some lawyer will pick this up and start a class action. All three vendors deserve to be crucified for this."